1. Field of the Invention
The present invention relates to a composition which can be used as a salting agent for preparation of processed meat products such as ham, bacon and roast pork where the composition contains transglutaminase and a compound which suppresses the activity of transglutaminase. In addition, the present invention relates to a pickle solution containing the composition wherein the viscosity of a protein-containing pickle does not significantly increase when the transglutaminase is added to the pickle. Therefore, the quality of processed meat products such as ham, bacon and roast pork which are produced with the pickle are significantly improved.
2. Description of Related Art
A curing step for permeating and dispersing a salting agent into raw meat materials is usually required for manufacturing processed meat products such as ham and bacon. These methods include a dry-curing method, a pickle curing method, and a pickle-injection method. The pickle curing method and the pickle-injection method are generally the most effective.
The pickles typically are a solution of a salting agent which is made up of sodium chloride and color-fixing agents. Additionally, polyphosphate and ascorbic acids are added to the pickle to improve the yield, water holding capacity, binding capacity and color-fixing ability and the like. Pickles also often contain seasonings, preservatives and additional color-fixing agents.
Pickles are often blended with various protein materials, e.g, egg white, whey protein, caseins such as sodium casein or soy bean protein, for the purpose of improving water retentivity, emulsification, food taste and texture, e.g., firmness, elasticity and bindability.
In addition, transglutaminase (hereinafter abbreviated as TGase) may be added to improve food taste, food texture and increasing slice yield (sliceability). TGase reacts with proteins in the pickle and with the proteins in the meat when the pickle permeates or is injected into the meat, which remarkably improves the physical properties of the resulting final product Since TGase effect is more pronounced in the presence of higher amounts of protein, the presence of TGase is highly important for pickles containing high amounts of protein materials. However, when TGase is used in increasing amounts with the higher concentrations of protein materials, the viscosity of the resulting pickle significantly increases.
Generally the pickle is left to stand in a low-temperature stock chamber for one to four days after preparation and before use, to insure that any powdery materials including protein materials are fully dissolved and to allow any bubbles or foam which are present to dissipate. TGase is often supplied as a powder and therefore is dissolved into the pickle with the protein materials. However, during this resting period the TGase which is added to the pickle, crosslinks and polymerizes the protein contained in the pickle thereby increasing the viscosity of the resulting pickle solution. This increase in viscosity makes subsequent use of the pickle difficult and if the method of producing the meat involves injection, makes the procedure almost impossible to conduct. There have been several attempts to modify the pickle containing TGase to avoid the increased viscosity.
Japanese Patent Application Laid-open Nos. 255426/1995 and 56303/1999 report techniques for suppressing the increase of pickle viscosity caused by TGase. The techniques involve controlling the quantities of caseins and soy bean protein which are highly reactive with TGase or using protein partial hydrolysates. These techniques suppress the viscosity increase with no influence on TGase activity, by reducing the effective TGase substrate concentration or by using proteins that are less susceptible to TGase action, e.g., protein partial hydrolysates. However, when the protein component of the pickle is changed the original purposes of the protein, such as imparting physical properties and water-holding capacity to the processed meat products, are significantly lower compared with the original types of proteins. This results in the undesirable property of poor elasticity and significant water release from the resulting product. When protein partial hydrolysates are used, the viscosity can be maintained for approximately one day, but is often not sufficiently suppressed during a longer term of storage. Since caseins and soy bean protein are used only in the form of their partial hydrolysates, the creation of diverse food taste, food texture and/or quality based on devised blending of various protein materials is greatly restricted. Thus, pickles containing TGase are limited when the TGase is used with lower amounts of protein. In addition, the pickles must be used within one day and the remaining unused portion is discarded.
On the background of the conventional techniques described above, it is an object of the present invention to provide a salting agent without any of the aforementioned disadvantages even after the salting agent is blended with TGase and with no need of any modification or treatment of protein materials added to the pickle.
The present inventors have investigated a solution to the aforementioned problems and have found to suppress the reaction by TGase in a pickle is accomplished by adding a TGase suppressing compound. This results in the ability to regulate TGase activity and allows maintenance of a low viscosity pickle. Thus, the present invention has been achieved.
The invention is essentially different from the conventional techniques by controlling the TGase activity whereby TGase can be added to pickle without modification to the preferable compounds of the pickle which would otherwise not be possible.
The present invention further provides a salting agent for meat processing, which comprises TGase and a compound which suppresses TGase activity; a pickle containing the salting agent; methods of making a processed meat using the salting agent and/or pickle; and the processed meats so obtained.